The investigation, Birth Planning: Values and Decisions, is studying the values and processes which underlie people's birth planning decisions. Subjects are 199 couples having 0, 1, 2, 3 or 4 children who are being interviewed and tested at yearly intervals over a three year period. Using subjective expected utility theory, the focus is upon the extent to which fertility outcomes can be predicted on the basis of positive and negative values associated with the decision to have and the decision not to have a (another) child. Preliminary results indicate that birth planning decisions are a rational process in which couples weigh the relative costs and benefits of having children and then behave in the way that will bring maximum benefit to themselves. The changes in motivations for and against childbearing as a function of parity are studied as well as situational factors influencing the family building process. A technique of birth planning counseling is one expected derivative of the investigation. BIBLIOGRAPHIC REFERENCE: Beach, L.R., Townes, B.D. & Campbell, F.L.: The use of hierarchical models in decision research. Paper presented at the Eleventh Annual Bayesian Conference on Decision Making, University of Southern California, Los Angeles, California, February, 1975. Townes, B. D., Beach, L.R., & Campbell, F.L.: The measurement of values associated with birth planning decisions. Paper presented at the Eighty-Third Annual Meeting of the American Psychological Association, Chicago, Illinois, August, 1975.